| abstract |
Oxidation catalyst complexes are disclosed for the treatment of exhaust gas emissions, such as the removal of unburned hydrocarbons (HC), and carbon monoxide (CO) and oxidation of NO to NO 2 . The catalyst composite includes two washcoat layers containing two different compositions of platinum group metals to optimize the NO 2 emissions of the catalyst composite. The basis for improvement in NO oxidation is to have one catalyst layer containing Pt but substantially free of Pd. Methods and systems using catalyst composites are also disclosed. |